US7933321B2 - Measuring system with a reference signal between a signal generator and a signal analyzer - Google Patents

Measuring system with a reference signal between a signal generator and a signal analyzer Download PDF

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Publication number
US7933321B2
US7933321B2 US10/480,323 US48032304A US7933321B2 US 7933321 B2 US7933321 B2 US 7933321B2 US 48032304 A US48032304 A US 48032304A US 7933321 B2 US7933321 B2 US 7933321B2
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signal
ref
signal generator
measuring system
test unit
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US20040233980A1 (en
Inventor
Wolfgang Kernchen
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Rohde and Schwarz GmbH and Co KG
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Rohde and Schwarz GmbH and Co KG
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/24—Testing correct operation
    • H04L1/242—Testing correct operation by comparing a transmitted test signal with a locally generated replica
    • H04L1/244—Testing correct operation by comparing a transmitted test signal with a locally generated replica test sequence generators
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/317—Testing of digital circuits
    • G01R31/31703—Comparison aspects, e.g. signature analysis, comparators
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/317—Testing of digital circuits
    • G01R31/31708—Analysis of signal quality

Definitions

  • the invention relates to a measuring system having a signal generator which produces a digitally modulated high frequency measuring signal by modulation with modulation data, which signal is supplied to the input of a test unit, and having a signal analyser which is connected to the output of the test unit and analyses the output signal of the test unit after demodulation thereof.
  • the signal analysers are for example spectrum analysers, vector signal analysers, time-domain analysers, code-domain analysers or system protocol testers. With these, in addition to the general measurements for instance of the level, of the spectrum etc., measurements are also implemented in which the received signal must be demodulated before analysis.
  • the signal generators produce high frequency measuring signals corresponding to the transmission standard, for example GSM (global System for Mobile Communication) standard or a wideband CDMA (Code Division Multiple Access) standard for the third generation mobile radio UMTS (Universal Mobile Telecommunication Standard).
  • the useful data are provided with error protection data in the transmitter before modulation, said error protection data enabling an error correction for the receiver to a limited degree, i.e. the incorrectly received bits or symbols can be corrected to a limited degree.
  • the energy per bit E b in relation to the noise output N 0 is smaller so that the error correction methods no longer permit complete correction of the bit or symbol errors and the reference bit sequence or reference symbol sequence cannot be completely reconstructed by using the error correction methods.
  • a further problem in the state of the art resides in the fact that synchronisation must take place with respect to various partial signal portions of the measuring signal.
  • the TDMA frame Time Division Multiple Access Frame
  • the synchronised bit sequences which the signal generator generates must be known to the signal analyser. This was only possible previously in that the synchronised bit sequences were input by hand via a keyboard into the signal analyser. This is laborious, leads to input errors and, in the case of frequent changing of the synchronised bit sequence, to a fairly long measuring time.
  • the object underlying the invention is therefore to produce a measuring system which is usable for the most varied of operating standards and with a high signal/noise ratio at a justifiable cost.
  • a direct connection is provided between the signal generator and the signal analyser, via which connection a reference signal of the signal generator is supplied directly to the signal analyser.
  • signals or data can be transmitted which enable a simple reconstruction of the reference bit sequence or the reference symbol sequence in the signal analyser without a reconstruction from the measuring signal using error correction methods being required for this purpose.
  • the reference signal can concern modulation data, the I/Q output signal of the I/Q modulator or for example the sequence of frequency values of an FSK method.
  • a synchronised bit sequence can also be transmitted for synchronisation with respect to partial signals of the measuring signal.
  • a corresponding correlator can be provided in the signal analyser. Furthermore a time shift device can be provided which corrects this time delay.
  • FIG. 1 a block diagram of an embodiment of the measuring system according to the invention
  • FIG. 2 a block diagram of a signal generator used in the embodiment of the measuring system according to the invention
  • FIG. 3 a block diagram of a signal analyser used in the embodiment of the measuring system according to the invention.
  • FIG. 4 a time diagram for explaining a GSM signal.
  • FIG. 1 shows a block diagram of the measuring system 1 according to the invention.
  • a signal generator 2 generates a digitally modulated high frequency measuring signal MS, for example a mobile radio signal according to the GSM standard or a W-CDMA standard.
  • the measuring signal MS is supplied in a high frequency position to an input 3 of a test unit (DUT Device Under Test) 4 .
  • the test unit 4 concerns for example a component of mobile radio technology, for example an amplifier of a base station.
  • a signal analyser 5 is in communication with the output 6 of the test unit 4 and receives its output signal OS.
  • the signal analyser 5 transforms the high frequency output signal OS into the baseband, implements a demodulation and analyses the demodulated signal in order to determine for example the bit error rate (BER Bit Error Rate) or the error vector magnitude (EVM Error Vector Magnitude) of a phase or frequency positioning error.
  • bit error rate BER Bit Error Rate
  • EVM Error Vector Magnitude error vector magnitude
  • a direct connection 7 is provided between the signal generator 2 and the signal analyser 5 .
  • the direct connection 7 can be configured either to be cable-connected or wireless, for example via transmitters and receivers which operate according to the Blue Tooth principle.
  • a reference signal Ref is supplied via the direct connection from the signal generator 2 to the signal analyser 5 .
  • FIG. 2 shows a highly simplified block diagram of the signal generator 2 , only the components relevant to the invention being illustrated.
  • pseudo-random modulation data MD are generated by a data source 6 .
  • the modulation data MD can however be supplied to the signal generator 2 also via an external interface.
  • the modulation data MD concern a sequence of data bits or data symbols or else a sequence of chips of a W-CDMA signal which are produced from the data bits after multiplication with a spread sequence.
  • These modulation data MD are supplied to a modulator, preferably an I/Q modulator 8 .
  • the I (in phase) signal and the Q (quadrature phase) signal is available, which is supplied to a high freqeuncy unit 10 .
  • the high frequency unit 10 brings the signal from the baseband firstly into an intermediate frequency position and then into the high frequency position in which the test unit 7 operates.
  • the modulation data MD are used as reference signal Ref in a preferred embodiment. It is however also conceivable to use the I/Q output signals of the I/Q modulator 9 as reference signal Ref, which is indicated in dotted lines in FIG. 2 . Furthermore, it is also conceivable to use an intermediate frequency signal of the high frequency unit 10 as reference signal Ref, which is likewise indicated in dotted lines in FIG. 2 .
  • FIG. 3 shows a highly simplified block diagram of the signal analyser 5 which is restricted to the components according to the invention.
  • the reference signal Ref supplied by the signal generator 2 concerns modulation data MD thereof.
  • the signal analyser 5 has a high frequency unit 11 which transforms the output signal OS of the test unit 4 from the high frequency position into the baseband and supplies it to a demodulator, preferably an I/Q demodulator 12 .
  • the demodulation data DD are available; this hereby concerns the actual symbol sequence or actual bit sequence of the output signal OS received from the test unit 4 .
  • a comparator device 13 In order to evaluate the bit error rate BER or in order to determine another error magnitude, for example the EVM (Error Vector Magnitude), a comparator device 13 is provided which compares the actual bit sequence or actual symbol sequence represented by the demodulation data DD with a reference bit sequence or reference symbol sequence. This reference bit sequence or reference symbol sequence is produced by the reference signal Ref supplied to the signal analyser 5 directly from the signal generator 2 via the connection 7 .
  • EVM Error Vector Magnitude
  • the reference signal Ref can be supplied directly to the comparator unit 13 .
  • running time differences between the signal path via the test unit 7 on the one hand and the direct connection 7 on the other hand are however present.
  • the time delay X produced by the running time differences can be determined by a correlator 14 , to the inputs of which the demodulation data DD on the one hand and the reference signal Ref on the other hand are supplied.
  • the reference signal Ref can be displaced by a time shift ⁇ t which corresponds to the time delay ⁇ determined by the correlator 14 . It is advantageous to transmit the modulation data MD via the connection 7 such that the modulation data MD arrive at the signal analyser 5 before the corresponding demodulation data DD are demodulated by the demodulator 12 .
  • the output of the time shift device 15 is supplied to an input of the comparator device 13 .
  • the comparator device 13 compares the reference bit sequence or reference symbol sequence given by the modulation data with the actual bit sequence or actual symbol sequence given by the demodulation data DD and can hence establish incorrect bits or incorrect symbols and for example evaluate them as bit error rate BER or as EVM (Error Vector Magnitude). Due to the fact that a correct reference signal Ref is always available via the connection 7 , the measurement can be implemented even with highly distorted signals and an evaluation of the error correction code (e.g. by means of a complex Viterbi decoder) is not required.
  • the reference signal Ref can be extended optionally with supplementary signals, which mark specific points in time in the data flow, for example the position of a frame of a timeslot of a burst or the beginning of a synchronisation sequence.
  • the synchronisation sequence used currently by the signal generator 2 can in addition be transmitted via the reference signal Ref directly to the signal analyser 5 .
  • the laborious manual input of the synchronisation sequence into the signal analyser 5 which was normal previously, is dispensed with.
  • the signal analyser 5 is hence also able to compare a large number of synchronisation sequences with the demodulation data DD since the signal analyser 5 is always informed about which synchronisation sequence the signal generator 2 is currently using. Hence the analysis becomes more rapid and/or the complexity in the signal analyser 5 is reduced.
  • the parallel observation of all possible training sequences TS is dispensed with.
  • FIG. 4 shows a TDMA (Time Division Multiple Access) frame.
  • a TDMA frame is divided into eight timeslots SL 0 , SL 1 , SL 2 , SL 3 , SL 4 , SL 5 , SL 6 and SL 7 .
  • a training sequence TS with 26 bits is situated respectively in the centre of each timeslot between the data bits DB.
  • this training sequence TS can be used.
  • the number of the total possible training sequences TS is relatively large.
  • the signal analyser 5 If it is not known to the signal analyser 5 which training sequence TS the signal generator 2 is using for a specific timeslot, then the signal analyser 5 must compare the demodulation data DD against all possible training sequences TS. However, if the signal analyser 5 obtains information from the signal generator 2 via the connection 7 about the training sequence TS currently used for a specific timeslot, then only a comparison against one single training sequence TS is necessary. If the signal generator 2 changes the training sequence TS, then the signal analyser 5 discovers this via the reference signal Ref.
  • the sequence of the frequency values, which are caused to hop by the FSK modulator, can be transmitted as reference signal Ref with an FSK (Frequency Shift Keying) System.
  • FSK Frequency Shift Keying

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)
US10/480,323 2001-06-26 2002-04-08 Measuring system with a reference signal between a signal generator and a signal analyzer Active 2027-12-09 US7933321B2 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE10130687.3 2001-06-26
DE10130687 2001-06-26
DE10130687A DE10130687A1 (de) 2001-06-26 2001-06-26 Meßsystem mit einem Referenzsignal zwischen einem Signalgenerator und einem Signalanalysator
PCT/EP2002/003861 WO2003003626A1 (fr) 2001-06-26 2002-04-08 Systeme de mesure a signal de reference entre un generateur de signaux et un analyseur de signaux

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US20040233980A1 US20040233980A1 (en) 2004-11-25
US7933321B2 true US7933321B2 (en) 2011-04-26

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EP (2) EP1608089B1 (fr)
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110271155A1 (en) * 2010-04-28 2011-11-03 Tektronix, Inc. Method and Apparatus for Measuring Symbol and Bit Error Rates Independent of Disparity Errors
US9912417B2 (en) 2014-07-31 2018-03-06 Rohde & Schwarz Gmbh & Co. Kg Measuring device and measuring method for start time synchronized signal generation

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10151173B4 (de) * 2001-10-17 2012-07-12 Rohde & Schwarz Gmbh & Co. Kg Verfahren zum Messen des Modulationsfehlers von digital modulierten Hochfrequenzsignalen
JP4287778B2 (ja) * 2004-03-31 2009-07-01 株式会社ケンウッド 通信品質判定装置及び通信品質判定方法
JP4772792B2 (ja) * 2005-07-26 2011-09-14 株式会社アドバンテスト シンボル変調精度測定装置、方法、プログラムおよび記録媒体
US7564896B2 (en) * 2005-08-12 2009-07-21 Litepoint Corp. Method for measuring multiple parameters of a signal transmitted by a signal generator
DE102007006084A1 (de) 2007-02-07 2008-09-25 Jacob, Christian E., Dr. Ing. Verfahren zum zeitnahen Ermitteln der Kennwerte, Harmonischen und Nichtharmonischen von schnell veränderlichen Signalen mit zusätzlicher Ausgabe davon abgeleiteter Muster, Steuersignale, Ereignisstempel für die Nachverarbeitung sowie einer Gewichtung der Ergebnisse
DE502008002482D1 (de) 2008-07-31 2011-03-10 Rohde & Schwarz Verfahren und Vorrichtung zur Herstellung einer quantisierbaren Phasenkohärenz zwischen zwei Hochfrequenzsignalen
DE102010010349A1 (de) * 2010-03-05 2011-09-08 Rohde & Schwarz Gmbh & Co. Kg Verfahren und System zum Testen einer Relaisstation
US11474137B2 (en) * 2020-09-18 2022-10-18 Rohde & Schwarz Gmbh & Co. Kg Test system

Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3794831A (en) * 1972-06-01 1974-02-26 Ibm Apparatus and method for monitoring the operation of tested units
US4774454A (en) * 1986-08-06 1988-09-27 Advantest Corporation Distortion measuring system method utilizing signal suppression
US4795963A (en) 1985-05-02 1989-01-03 Hitachi, Ltd. Test method of A/D converter
US5157652A (en) * 1989-07-28 1992-10-20 Hewlett-Packard Company Measurement of characteristics of broadcast optical networks
US5260648A (en) * 1989-05-29 1993-11-09 Brust Hans Detlef Process and system for rapid analysis of the spectrum of a signal at one or several points of measuring
DE19515037A1 (de) 1994-04-22 1995-10-26 Advantest Corp Digitale Signalmodulationsanalysevorrichtung
US5784406A (en) 1995-06-29 1998-07-21 Qualcom Incorporated Method and apparatus for objectively characterizing communications link quality
US5838672A (en) * 1995-10-03 1998-11-17 Nokia Mobile Phones Ltd. Method for measuring the timing of a received signal in a communication system and mobile station implementing the method
WO2000007302A1 (fr) 1998-07-27 2000-02-10 Gte Government Systems Corporation Technique de detection et d'evitement de signaux parasites
US6084868A (en) * 1994-12-20 2000-07-04 Nokia Telecommunications Oy Base station having transmitter power adjustment system
US6112067A (en) 1996-03-27 2000-08-29 Anritsu Corporation Radio communication analyzer suited for measurement of plurality of types of digital communication systems
WO2000079708A1 (fr) 1999-06-18 2000-12-28 Societe Europeenne Des Satellites S.A. Procede et appareil pour determiner les caracteristiques de composants d'une voie de transmission
JP2001056359A (ja) 1999-06-09 2001-02-27 Advantest Corp 半導体試験装置
DE10055456A1 (de) 1999-11-12 2001-05-17 Advantest Corp Halbleiterprüfsystem zur Prüfung von Mischsignalbauteilen
US6484124B1 (en) * 2000-05-22 2002-11-19 Technology Service Corporation System for measurement of selected performance characteristics of microwave components
US6775840B1 (en) * 1997-12-19 2004-08-10 Cisco Technology, Inc. Method and apparatus for using a spectrum analyzer for locating ingress noise gaps

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3794831A (en) * 1972-06-01 1974-02-26 Ibm Apparatus and method for monitoring the operation of tested units
US4795963A (en) 1985-05-02 1989-01-03 Hitachi, Ltd. Test method of A/D converter
US4774454A (en) * 1986-08-06 1988-09-27 Advantest Corporation Distortion measuring system method utilizing signal suppression
US5260648A (en) * 1989-05-29 1993-11-09 Brust Hans Detlef Process and system for rapid analysis of the spectrum of a signal at one or several points of measuring
US5157652A (en) * 1989-07-28 1992-10-20 Hewlett-Packard Company Measurement of characteristics of broadcast optical networks
DE19515037A1 (de) 1994-04-22 1995-10-26 Advantest Corp Digitale Signalmodulationsanalysevorrichtung
US6084868A (en) * 1994-12-20 2000-07-04 Nokia Telecommunications Oy Base station having transmitter power adjustment system
US5784406A (en) 1995-06-29 1998-07-21 Qualcom Incorporated Method and apparatus for objectively characterizing communications link quality
US5838672A (en) * 1995-10-03 1998-11-17 Nokia Mobile Phones Ltd. Method for measuring the timing of a received signal in a communication system and mobile station implementing the method
US6112067A (en) 1996-03-27 2000-08-29 Anritsu Corporation Radio communication analyzer suited for measurement of plurality of types of digital communication systems
US6775840B1 (en) * 1997-12-19 2004-08-10 Cisco Technology, Inc. Method and apparatus for using a spectrum analyzer for locating ingress noise gaps
WO2000007302A1 (fr) 1998-07-27 2000-02-10 Gte Government Systems Corporation Technique de detection et d'evitement de signaux parasites
JP2001056359A (ja) 1999-06-09 2001-02-27 Advantest Corp 半導体試験装置
WO2000079708A1 (fr) 1999-06-18 2000-12-28 Societe Europeenne Des Satellites S.A. Procede et appareil pour determiner les caracteristiques de composants d'une voie de transmission
DE10055456A1 (de) 1999-11-12 2001-05-17 Advantest Corp Halbleiterprüfsystem zur Prüfung von Mischsignalbauteilen
US6484124B1 (en) * 2000-05-22 2002-11-19 Technology Service Corporation System for measurement of selected performance characteristics of microwave components

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110271155A1 (en) * 2010-04-28 2011-11-03 Tektronix, Inc. Method and Apparatus for Measuring Symbol and Bit Error Rates Independent of Disparity Errors
US8386857B2 (en) * 2010-04-28 2013-02-26 Tektronix, Inc. Method and apparatus for measuring symbol and bit error rates independent of disparity errors
US9912417B2 (en) 2014-07-31 2018-03-06 Rohde & Schwarz Gmbh & Co. Kg Measuring device and measuring method for start time synchronized signal generation

Also Published As

Publication number Publication date
DE50204405D1 (de) 2006-02-09
DE50212747D1 (de) 2008-10-16
EP1402665B1 (fr) 2005-09-28
DE10130687A1 (de) 2003-01-02
EP1402665A1 (fr) 2004-03-31
EP1608089A1 (fr) 2005-12-21
WO2003003626A1 (fr) 2003-01-09
US20040233980A1 (en) 2004-11-25
EP1608089B1 (fr) 2008-09-03

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